TileList seems to runs slow when you repeatedly and quickly
drag the thumb back and forth; sometimes it simply crashes

TypeError: Error #1009: Cannot access a property or method of
a null object reference.
at
mx.controls.listClasses::TileBase/mx.controls.listClasses:TileBase::scrollHorizontally()
at
mx.controls.listClasses::TileBase/mx.controls.listClasses:TileBase::scrollHandler()
at
flash.events::EventDispatcher/flash.events:EventDispatcher::dispatchEventFunction()
at flash.events::EventDispatcher/dispatchEvent()
at mx.core::UIComponent/dispatchEvent()
at mx.controls.scrollClasses::ScrollBar/
http://www.adobe.com/2006/flex/mx/internal::dispatchScrollEvent() at
mx.controls.scrollClasses::ScrollThumb/mx.controls.scrollClasses:ScrollThumb::mouseMoveHa ndler()
at [mouseEvent]